Hydraulic ram apparatus



Dan. v29, 1970 H. v. NORTON ETAL 31,550,375

HYDRAULIC RAM APPARATUS 4 Sheets-Sheet 1 Filed April 18, 1969 IL Lnuumuriuu mm ly vm Q GE INVENTORS HUBERT v. N LE BY D0 an: 5 N32118:!MR3 s mon'rou ATTORNEY Dec. 29, 1970 H. v. NORTON ETAL 3,550,375

HYDRAULIC RAM APPARATUS Filed April 18, 1969 4 Sheets-Sheet 2 BY DOUGLA3 E.

ATTORNEY H. v. NORTON ETAL 3 ,550,375

HYDRAULIC RAM APPARATUS Dec. 29, 1970 4 Sheets-Sheet 5 2 STTT VI RRRR CL0000 N NNN R O e T V T N A VI B Filed April 18, 1969 Dec. 29, 1970 H. v.NORTON ETAL 3,550,375

HYDRAULIC RAM APPARATUS 4 Sheets-Sheet 4 Filed April 18, 1969 mw GIUnited States Patent 3,550,375 HYDRAULIC RAM APPARATUS Hubert VeareNorton, Leslie Buckingham Norton,

and Douglas Edwin Norton, Smallfield, Horley, England, assignors toNorton Tool Company Limited, Smallfield, Horley, Surrey, England FiledApr. 18, 1969, Ser. No. 817,324 Claims priority, application GreatBritain, Apr. 22, 1968, 18,826/ 68 Int. Cl. lFlSb /18 US. CI. 60-52 8Claims ABSTRACT OF THE DISCLOSURE Hydraulic ram apparatus supplied by asingle pump which delivers fluid to an actuating element for a reservoirunit whereby a large volume of fluid is delivered to the ram from thereservoir unit to produce a fast approach movement. A pressure-sensitivechange-over valve switches the pump delivery from the reservoir actuatorunit direct to the ram when the ram encounters resistance, to supply asmaller volume of fluid at high pressure for the working movement of theram.

This invention relates to hydraulic ram apparatus more particularly, butnot exclusively, the hydraulic ram apparatus of an hydraulic press.

In hydraulic ram apparatus it is sometimes desirable for the movablemember of the ram to make a fast approach movement, which requires alarge flow of fluid at low pressure, followed by a short workingmovement which requires a small flow of fluid at high pressure.

It is an object of the present invention to provide a means ofsatisfying these diverse pressure and flow rate requirements using asingle pump in conjunction with a simple hydraulic system.

According to the present invention, hydraulic ram apparatus comprises apump to supply hydraulic fluid under pressure to the working chamber ofthe ram through a pressure-sensitive change-over valve adapted to openonly when the pressure in the working chamber attains a predeterminedvalue higher than that during the approach movement, the pump also beingin communication with the working chamber of a hydraulic cyclinder andpiston unit of relatively small diameter (herein termed the reservoiractuator unit) the movable member of which is coupled to the movablemember of a hydraulic cyclinder and piston unit of relatively largediameter (hereinafter termed the reservoir unit) the cylinder chamber ofwhich communicates with the working chamber of the ram.

The change-over valve remains closed during the approach stroke, thesupply of fluid in large volume and at low pressure required for theapproach stroke being delivered to the working chamber of the ram fromthe large diameter cylinder chamber of the reservoir unit, this fluidbeing discharged from the reservoir unit by the advancement of themovable member thereof. The latter movement is produced by the movablemember of the small diameter reservoir actuator unit which is advancedby the pump pressure acting upon it. Owing to the differences ineffective diameters of the reservoir unit and of the reservoir actuatorunit, only a small flow of fluid to the latter (but under mediumpressure) will deliver a large flow of fluid from the former at; lowpressure.

At the end of the approach movement, when the movable member of the ramencounters increased resistance, e.g. by coming up against a workpiece,the pressure in the system builds up until it attains the predeterminedvalue at which the change-over valve is set to open. When ice this valveopens, fluid can pass directly from the pump to the working chamber ofthe ram, thereby applying full pump pressure to the movable member ofthe ram.

The cylinder space of the reservoir unit behind the piston therein maybe connected by a non-return valve to a source of fluid so that fluid isadmitted to this space as the movable member of the reservoir unit isbeing advanced during the approach movement of the ram. When thepressure in the system rises at the end of the approach movement, asmentioned above, the fluid in this space cannot escape through thenon-return valve and is trapped, thereby preventing the movable memberof the reservoir unit from being forced back when the change-over valveopens. Some means is necessary for venting the fluid from this space topermit return of the movable member of the reservoir unit on the returnstroke of the hydraulic ram, and for this purpose the space may beconnected to a line which communicates with the working chamber of theram (e.g. a fluid return line), through a non-return valve adapted toopen only when the pressure in the space exceeds the pressure in thereturn line (and hence in the working chamber of the ram) Thus, when avalve in the return line is opened to permit return of the movablemember of the ram, the pressure in the return line will dropsufficiently to permit the last-mentioned non-return valve to open topermit fluid to escape from the said space so that the movable member ofthe reservoir unit is returned to its original position with thereservoir cylinder full of fluid, in readiness for the next workingstroke.

It will be appreciated that in. the arrangement just referred to, inwhich the cylinder chamber of the reservoir unit communicates directlywith the working chamber of the ram, the reservoir unit. will be exposedto the maximum working pressure of the hydraulic system and thereforemust be sufliciently robust to withstand this high pressure.

In another form of the invention, the reservoir unit communicates withthe working chamber of the ram through an unload valve. This valvepermits fluid to flow from the reservoir unit to the working chamber ofthe ram during the approach movement of the ram but is automaticallyclosed when the pressure in the working chamber begins to rise at theend of the approach movement, thereby shutting off communication betweenthe high pressure portion of the hydraulic system and the reservoirunit. The reservoir unit therefore need not be made sufficiently strongto withstand the full working pressure and can be of relatively lightand inexpensive construction.

In this form of the invention which includes an unload valve, provisionhas to be made for opening this valve to permit discharge of fluid fromthe working chamber of the ram to the reservoir unitduring the returnstroke, e.g., automatically, by providing a pressure control for openingthe unload valve in response to the pressure in the return chamber ofthe ram. The means for opening the unload valve need not, however, bepressure-actuated; it could be a mechanical connection operated by thecontrol lever or the like which initiates the return stroke of the ram.When the unload valve is opened, fluid will be discharged from theworking chamber of the ram through this open valve back into thecylinder chamber of the reservoir unit. However, since the latter partof the movement of the hydraulic ram on its working stroke had beenachieved by admission of high pressure fluid through another line andnot through the then closed unload valve, more fluid must be dischargedto and through the reservoir unit than was originally delivered from itduring the approach portion of the working stroke. For this purpose, thereservoir unit may be provided with a return by-pass passage, whichpermits fluid to pass back through the reservoir unit as soon as themovable member of the reservoir unit has returned to its originalposition.

The apparatus may have a number of refinements and modifications.

For example, there may be a bypass passage around the pressure-sensitivechange-over valve, which iby-pass pasage is normally closed by amanually openable valve. When this valve is opened, direct communicationis established betwen the pump and the working cylinder of the ram sothat the reservoir unit and the change-over valve cease to be effectiveand the fast approach system is thereby rendered inoperative.

There may also be an apparatus control unit actuated against spring biasthrough a toggle link, for example by a pedal, which pedal is depressedto initiate a working stroke and released to initiate a return stroke.

Automatic initiation of the return stroke may be effected by providing apressure-sensitive element adapted to collapse the toggle link when theworking pressure attains a predetermined upper limit.

Various additional elements such as safety valves and overridingpressure release valves, as provided in conventional hydraulic ramapparatus, may also be installed in the present apparatus.

The invention may be performed in various ways, and two specificembodiments will now be described by way of example With reference tothe accompanying drawings, in which:

FIG. 1 is a diagram showing the spatial relationship of FIGS. 1A and 1B;

FIG. 1A is the upper half of a diagram illustrating the firstembodiment;

FIG. 1B is the lower half of the diagram of the first embodiment;

FIG. 2 is a diagram showing the spatial relationship of FIGS. 2A and 2B.

FIG. 2A is the upper half of a diagram illustrating the secondembodiment; and

FIG. 2B is the lower half of the diagram of the second embodiment.

Referring to FIGS. 1A and 1B, there is shown in FIG. 1A the hydraulicram of an hydraulic press. The other mechanical parts of the press areconventional and do not need to be illustrated to enable the inventionto be understood.

The moveable element of the ram is a cylinder 11 which can move up anddown in a fixed guide 12 secured to the frame 13 of the press. A collar14 is attached to a screwthreaded portion 15 of the cylinder 11, andacts as an adjustable trigger for automatic repetition operation of thepress in a manner to be described. Within the cylinder 11 is a piston 16which is fixed to the frame 13. The cylinder space 17 below the pistonconstitutes the working chamber of the ram and is in communication witha fluid supply and return line 18 through a bore 19 in the piston 16.The cylinder space 20 above the piston 16 constitutes the return chamberof the ram and is in communication with another fluid supply and returnline 21 through another piston bore 22. When fluid is supplied throughthe line 18 and returned through the line 21, the cylinder 11 is forceddownwards to perform a working stroke, whereas when fluid is suppliedthrough the line 21 and returned through the line 18 the cylinder israised, performing its return stroke.

The hydraulic fluid for both the working and return strokes is suppliedby a pump 25 (FIG. 1B). There is a conventional excess pressure reliefvalve connected to the output side of the pump, and the fluid thenpasses on through a main delivery line 27 to a gallery 28 in a maincontrol valve unit 29 (FIG. 1A). In this unit there are two valves 30and 31 actuated by a rocking lever 32 so that when the valve 30 is opento the gallery 28 the valve 31 is closed, and vice versa. When the valve30 is open, fluid can flow from the gallery 28 to a line 33 having twobranch lines, 35 and 36 respectively. fQ f performing the working strokeof the cylinder 11 in a manner to be described in more detail below.When the valve 31 is open, the fluid can flow from the gallery 28 to theline 21 for performing the return stroke of the cylinder 11. Also, whenthe valve 30 is open to the gallery 28, the valve 31 vents the line 21,and when the valve 31 is open to the gallery 28, the valve 30 vents theline 33. The venting apertures beneath the valves 30 and 31 maycommunicate with a fluid storage vessel (not shown). The ways in whichthe main control Valve unit 29 may be operated will be described in moredetail below.

Between the lines 33 and 36 there is a manually 0perable valve 37 whichis closed when the reservoir unit 52 of the invention is to be operableand is opened only if it should be desired to operate the press withthis unit out of action, by-passing the unit 52 and the change-overvalve 41 referred to below. The line 18 communicates directly through aline 38 with the actuating cylinder 40 of the pressure-sensitivechange-over valve 41. The line 35 from the line 33 leads to an inletport 42 of this change-over valve. The outlet port 43 of the change-overvalve communicates with the line 18 through lines 44 and 38.

The line 35 also leads to the small diameter working chamber 47 of areservoir actuator unit 48. This unit consists of a fixed tubular piston49 the bore of which communicates with the line 35, and slidable thereona cylinder 50. The cylinder 50 is an integral extension of the piston 51of the reservoir unit 52, which piston is slidable in a fixed reservoircylinder 53. The cylinder space 54 above the piston 51 constitutes areservoir of fluid for performing a fast approach portion of the workingstroke; it is in direct communication with the line 18. The space 55 inthe cylinder 53 below the piston 51 can be filled with fluid from anysuitable source (not shown) as the piston 51 is raised, throughnon-return valve 56. The space 55 also communicates with the line 35through a non-return valve 57, such that fluid cannot flow from the line35 into the space 55 but can blow in the reverse direction when the line35 is vented on the return stroke.

On the return stroke, fluid can flow out of the line 18 through a returnline which communicates through a non-return valve 61 with the ventedline 35. The return line 60 also serves to put the line 18 incommunication with a branch 62 leading to an auxiliary control valveunit 63.

The auxiliary control valve unit has an adjustable spring-loaded valve64 which opens when the pressure in the line 18 attains a pre-setmaximum value. When this occurs, fluid is admitted to a chamber 65,thereby forcing out a piston 66. The chamber 65 can be vented manuallyby a valve 67 actuated by a hand lever 68. Also, the chamber 65communicates with the line 62 through a line 69 equipped with anon-return valve 70.

The rocking lever 32 which actuates the main control valve unit 29 isconnected to the upper end of the upper link 72 of a toggle linkage 72,73. The lower link 73 of this linkage is connected to a pedal 74, andthe linkage is biased towards the right in the drawing by a tensionspring 75. The piston 66 engages the toggle linkage near its centrepivot. The arrangement is such that normally the toggle linkage acts asa strut, so that when the pedal 74 is depressed the toggle linkage israised, to tilt the rocking lever 32 into the working stroke position asshown in the drawing. However, when the pressure in the return line 62becomes high enough to open the valve 64 and push out the piston 66,this collapses the toggle linkage so that it will not transmit the pedalmovement to the rocking lever 32.

The rocking lever 32 is also connected through a link 76 (FIG. 1A) to alever 77 which is biased by a tension spring 78 so as to tend to forcethe link 76 downwards, to tilt the rocking lever 32 towards the returnstroke position with the valve 31 exposing the line 21 to the gallery218. Mounted in the frame 13 so as to be capable of limited upwardmovement is a sleeve 79 in which is adjustably mounted a pin 80. The pin80 may be so adjusted that its lower end is engaged by the collar 14towards the end of the return stroke, so that the sleeve 79 is therebylifted, to raise the lever 77 and the link 76. Alternatively, the pin 80can be raised so that it is clear of the collar 14 at all times.

The apparatus described operates as follows.

Assume that the cylinder 11 is in its upper position, ready to begin aworking stroke. The pump is running and supplying fluid to the gallery28 of the main control valve unit 29. The valve 31 is open and the pumpis maintaining suflicient pressure in the return chamber 20 to maintainthe ram cylinder 11 in this position. All lines and cylinder spaces arefull of fluid at relatively low pressure, and the reservoir piston 51 isin its bottom position. The pin 80 is raised clear of the collar 14. Ifnow the pedal 74 is depressed, the toggle linkage 72, 73 will tilt therocking lever 32 over into the position shown in the drawing so that theline 21 and the return chamber 20 are vented, and fluid is suppliedthrough the now open valve to the lines 33 and 35. The pressure of thefluid in the line 35 acts in the working chamber 47 of the reservoiractuator unit 48 to raise the piston 51 and force a much larger volumeof fluid from the reservoir cylinder space 54 through the line 18 intothe working chamber 17 of the hydraulic ram. This causes the ramcylinder 11 to make a fast approach stroke, until it encountersresistance to its further progress. At the same time, fluid enters thecylinder space 55 below the reservoir piston through the non-returnvalves 56. The further advance of the reservoir piston 51 is likewiseresisted and pressure builds up in the line 35 and in the lines 18 and38. When the pressure in the line 38 has risen sufliciently to depressthe piston in the cylinder of the change-over valve 41. this opens thechangeover valve, thereby allowing fluid to flow from the line 35through the ports 42 and 43, and through the line 44 to the line 18, sothat pump pressure is now applied to the hydraulic ram through line 27,gallery 28, valve 30, line 35. change-over valve 41 and line 18. Thispressure is also applied to the reservoir piston 51, but this piston isnow hydraulically locked by the fluid trapped in the space beneath it.This fluid cannot escape through the valve 57 because a higher pressureprevails in the line 35. The hydraulic ram therefore completes itsworking stroke under direct pump pressure.

When the pressing operation is complete the operator releases the pedal74, enabling the spring 78 to swing over the rocking lever 32. Thisraises the valve 30, venting the line 35. This enables the non-returnvalves 57 and 61 to open, permitting the reservoir piston 51 to descendand the cylinder space 54 to refill, and also allowing fluid to flow outof the ram chamber 17 through the line 18 and the return line 60. At thesame time, the valve 31 admits pumped fluid from the gallery 28 to theline 21, so that it enters the ram cylinder space 20 and causes the ramto perform its return stroke. The next working stroke can then beinitiated by depresing the pedal 74 again.

If desired, the apparatus can be arranged to repeat its operationsautomatically. This is done by setting the auxiliary control valve unit63 so that the valve 64 is opened when the pressure on the workingstroke has built up to a predetermined maximum value. This causes thepiston 66 to move out and collapse the toggle linkage so that therocking lever 32 is pulled over by the spring 78 from its working strokeposition to its return stroke position. Also, the pin 80 is adjusted sothat it is raised by the collar 14 near the end of the return stroke,thereby raising the sleeve 79 and moving the rocking lever back from thereturn stroke to the working stroke position so that the cycle isrepeated. During the return stroke, fluid escapes from the chamber 65 ofthe auxiliary control valve unit 63 through the non-return valve 70, sothat the toggle linkage can re-set.

Semi-automatic operation can also be. achieved by utilizing theauxiliary control valve unit 63 but not the pin 80, or vice versa.

In the embodiment illustrated in FIG. 1A and 1B, the reservoir unit 52is at all times in communication with the working chamber 17 of the ramand consequently exposed to the full working pressure, which may be veryhigh. Consequently, the reservoir unit 52 must be of robustconstruction.

In the embodiment illustrated in FIGS. 2A and 2B the reservoir unit 82is not exposed to pressures much above those attained during theapproach movement of the ram and can therefore be of much lighterconstruction.

Many of the parts shown in FIGS. 2A and 2B correspond to parts shown inFIGS. 1A and 1B and have been given the same reference numerals.

So far as the pump 25, the main control valve unit 29, thepressure-sensitive change-over valve 41, the hydraulic ram 10 and thevarious pedal and manual and automatic control devices are concerned,these are unchanged. However, the cylinder space 54 of the reservoirunit 82 does not communicate at all times with the working chamber 17 ofthe ram. Instead, the cylinder space 54 communicates through a line 83,with an unload valve 84. This valve has three chambers, a chamber 85 inpermanent communication with the main fluid supply line 18 to the ramworking chamber, an intermediate chamber 86 with which the line 83 fromthe reservoir unit communicates, and an actuating chamber 87. There is apassageway 88 between the chambers 86 and 85 which can be opened andclosed by a valve 89. The actuating chamber 87 communicates with thereturn line 21 from the ram through a line 90.

The reservoir unit 82 comprises a thin-walled cylinder 91 in which canslide a piston comprising two parts, namely an inner part 92, and anouter part 93 which is slidable axially relative to the inner part 92through a small distance between a flange 94 and a shoulder 95 on theinner part 92. There is also an annular clearance 96 between the bore ofthe outer part 93 and the central portion of the inner part 92. Theflange 94 is interrupted or perforated so as to permit fluid to flowdown from the space 54 when the outer piston part 93 is raised clear ofthe shoulder 95", thereby in effect bypassing the piston. When the outerpiston part 93 is in contact with the shoulder 95 such flow isprevented. A lower portion 97 of the inner part 92 serves as thecylinder of the reservoir actuator unit 48, as in the case of theprevious embodiment. Fluid can pass freely into the lower cylinder space98 below the piston 92, 93 through ports 99 in the base of the cylinder91. Rods 100 project upwardly from the base of the cylinder.

The embodiment illustrated in FIGS. 2A and 2B works as follows.

Assume that the cylinder 11 is in its upper position, ready to begin aworking stroke. The pump 25 is running and supplying fluid to thegallery 28 of the main control valve unit 29. The valve 31 is open andthe pump is maintaining suflicient pressure in the return chamber 20 tomaintain the ram cylinder in its upper position. All lines and cylinderspaces are full of fluid at relatively low pressure, and the reservoirpiston assembly 92, 93 is in its bottom position. In this position theannular outer part 93 of the piston is resting on the rods 100 so as tolie clear of the shoulder 95 so that fluid in the reservoir cylinderspace 54 can escape downwards through the piston 92, 93.

When the pedal 74 is depressed, the line 21 and the return chamber 20are vented and fluid is supplied through the now open valve 30 to thelines 33 and 35, as in the previous embodiment. The pressure of thefluid in the line 35 acts in the working chamber 47 of the reservoiractuator unit 48 to raise the inner piston part 92 until the shoulder 95contacts the outer piston part 93, thereby closing the escape route forfluid from the reservoir cylinder space 54. As the piston parts 92, 93are raised further together, they force fluid from the reservoircylinder space 54 through the line 83 into the intermediate chamber 86of the unload valve 84. The volume of this fluid is much greater thanthe volume admitted to the Working chamber 47 of the reservoir actuatingunit. The pressure of the fluid discharged from the reservoir unit issufficient to open the unload valve 84 and so permit the fluid to flowon through the line 18 into the working chamber 17 of the hydraulic ram.This causes the ram cylinder 11 to make a fast approach movement untilit encounters resistance to its progress. Thereupon the pressure buildsup in the line 18 and moves the piston in the cylinder 40 of thechange-over valve 41 to the left (FIG. 2B) to open the change-overvalve, allowing fluid to flow from the line 33 through the ports 42 and43 and through the line 44 direct to the line 18. This build-up ofpressure in the line 18 is also suflicient to close the unload valve 84,thereby isolating the line 83 and the reservoir unit 82 from the workingchamber of the ram to which high pressures are now applied.

Termination of the working stroke can be effected either by the operatorreleasing the pedal 74 or automatically by the auxiliary valve unit 63as in the previous embodiment. The opening of the valve and theconsequent release of pressure in the lines 33, permits the piston 92,93 of the reservoir unit 82 to descend. At the same time, the build-upof pressure in the return line 21 and the line consequent upon theopening of the valve 31 introduces pressure into the actuating chamber87 of the unload valve 84 so that this valve is opened once more,allowing fluid to pass back through the line 83 into the cylinder space54 of the reservoir unit.

However, the volume of fluid discharged from the working chamber 17 isgreater than the volume of the cylinder space 54, because additionalfluid was introduced into the working chamber after the unload valve 84was closed on the working stroke. Provision must be made for releasingthis excess volume of fluid. This occurs when the piston 92, 93approaches its lowest position. At this happens the outer piston part 93comes to rest on the rods 100 but the inner piston part 92 continues todescend for a short distance, thereby opening a clearance between theouter piston part 93 and the shoulder 95 through which the excess oilcan escape down through the ports 99.

On completion of the return stroke a further working stroke can beinitiated either by actuation of the pedal 74 or automatically asdescribed in the case of the first embodiment.

What we claim as our invention and desire to secure by Letter Patent is:

1. Hydraulic ram apparatus comprising a cylinder and piston unitdefining a working chamber therein, a pump, a line from the pump to apressure-sensitive change-over valve, a line from said change-over valveto said working chamber, an operative connection between saidchange-over valve and said working chamber adapted to open saidchange-over valve when the pressure in said working chamber attains apredetermined value, a reservoir unit comprising a hydraulic cylindermember and a piston member of relatively large diameter and defining areservoir chamber therein, one of said members being movable, a linefrom said reservoir chamber to said working chamber, a reservoiractuating unit comprising a cylinder member and a piston member ofrelatively small diameter one of which members is movable together withsaid movable member of said reservoir unit, and a line from said pump tosaid reservoir actuating unit.

2. Apparatus according to claim 1 in which said members of saidreservoir unit define a cylinder space separated from said reservoirchamber by said piston member, and including a non-return valve forfluid openable inwards towards said cylinder space.

3. Apparatus according to claim 2 including a nonreturn valve for fluidopenable outwards from said cylinder space to a line communicating withsaid working chamber.

4. Apparatus according to claim 1 in which there is an unload valve insaid line from said reservoir chamber to said working chamber to permitflow of fluid from said reservoir chamber to said working chamber onlywhen the pressure in said working chamber is below a predeterminedvalue.

5. Apparatus according to claim 4 including means to automatically opensaid unload valve to permit return flow of fluid from said workingchamber to said reservoir chamber during a return stroke of said ram,said means being responsive to pressure in a return chamber of said ram.

6. Apparatus according to claim 4 including means defining a returnby-pass passage in said reservoir unit to permit flow of fluid from saidcylinder space when said movable member of said reservoir unit hasreturned to its original position.

7. Apparatus according to claim 1 including a bypass line around saidpressure-sensitive change-over valve and a normally closed valve in saidby-pass line.

8. Apparatus according to claim 1 including a control unit, spring meansurging said control unit in one direction, a toggle linkage, a controlmember adapted to urge said control unit in the opposite directionthrough said toggle linkage, a pressure-sensitive element, means ofconnecting said pressure-sensitive element to said working chamber, andan operative connection between said pressure-sensitive element and saidtoggle linkage to collapse said toggle linkage when the pressure in saidworking chamber attains a predetermined upper limit.

References Cited UNITED STATES PATENTS 2,403,391 7/1946 Muir 60--52H.F.2,827,766 3/1958 Hufford 6052H.F.X 3,310,943 3/1967 Horetzke 60--52H.F.X

FOREIGN PATENTS 797,753 7/1958 Great Britain 60-52H.F.

EDGAR W. GEOGHEGAN, Primary Examiner US. Cl. X.R. 91-2

